The time course of facial emotion processing remains debated. Recent studies have suggested that facial features specific to an emotion are critical for accurate facial emotion discrimination. We investigated whether fixating on these diagnostic facial features impacted the time course of facial emotion processing and whether this varied as a function of task. ERPs were recorded in response to presentations of fearful, joyful or neutral faces while fixation was restricted to the left eye, right eye, nose or mouth using an eye-tracker. In the explicit emotion discrimination task, emotion only impacted the Early Posterior Negativity (EPN) (230- 250ms post-stimulus) that was largest for fearful faces, followed by happy, and smallest for neutral faces. In the oddball detection task where participants responded to flower target images, fearful and neutral faces elicited larger responses than happy faces on the P1 component (80- 130ms post-stimulus); fearful faces also elicited larger responses than neutral faces on the face-sensitive N170 component (120-220ms post-stimulus), but no modulation by emotion was seen on the EPN. In addition, in both tasks, the N170 was larger for fixation to the left and right eye compared to the nose and mouth regardless of facial emotion. Thus, fixation on diagnostic features did not impact the time course of emotion processing but the N170 response to eyes suggests the involvement of an eye-detector in the face structural encoding stages. Results also suggest earlier processing of emotion in expression-irrelevant compared to expression-relevant tasks.